A rolling bearing is used in various technical applications in order to support and guide parts that can move relative to each other, in particular, rotate relative to each other, in machines and to absorb the effective external forces and transfer them to a housing or the like. For example, the shaft of a turbocharger is supported in a motor vehicle with a rolling bearing constructed as a two-row angular contact ball bearing.
A rolling bearing can be exposed to very high stresses during operation as is the case, for example, if used in a modern turbocharger that can reach very high rotational speeds of approximately 300,000 revolutions per minute. Such a rolling bearing must exhibit a reliable operating behavior that is as wear free as possible even under high operating temperatures and at high rolling loading between the rolling bodies and the raceway of a bearing ring.
A bearing ring for such applications is therefore typically produced from an alloyed steel and hardened by an additional heat treatment. DE 10 2008 023 158 A1 discloses, for example, a rolling bearing part, in particular, a bearing ring that is made from a low-alloy steel. The rolling bearing part is operated, in particular, in corrosive environments. Through multiple treatment steps, improved corrosion resistance with sufficient mechanical strength should be achieved for the rolling bearing part. In one treatment step, the surface zone of the bearing ring is hardened by a thermochemical treatment method. Through nitriding or nitrocarburizing that is not described in more detail, a hard surface zone with a thickness of 15 to 25 μm is generated. The thickness of this surface zone, however, is not sufficient especially for the bearing ring of a rolling bearing that is exposed to very high loads like those that occur, for example, in the support of the shaft of a turbocharger.